Sex-specific Habitat Use and Responses to Fragmentation in an Endemic Chameleon Fauna

Chameleons are an understudied taxon facing many threats, including collection for the international pet trade and habitat loss and fragmentation. A recent field study reports a highly female-biased sex ratio in the Eastern Arc Endemic Usambara three horned chameleon, Trioceros deremensis, a large, sexually dimorphic species. This species is collected for the pet trade, and local collectors report males bring a higher price because only this sex has horns. Thus, sex ratios may vary due to differential rates of survival or harvesting. Alternatively, they may simply appear to be skewed if differences in habitat use biases detection of the sexes. Another threat facing chameleons is that of habitat loss and fragmentation. Despite enormous amounts of research, the factors of fragmentation that different species respond to is still under debate. Understanding these responses is important for current mitigation efforts as well as predicting how species will respond to future habitat alteration and climate change. My study suggests that differences in survival and detection may explain much of the observed seasonal sex skew in adult T. deremensis. Within fragmented habitat chameleons consistently responded more to edge effects and vegetative characteristics associated with fragmentation than to area or isolation effects. This may bode poorly for chameleon populations in the coming decades as climate change further alters vegetative communities and exacerbates edge effects.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2012

Author dc:creator

• Shirk, Philip

Contributors dc:contributor

• James Vonesh

• habitat fragmentation
• Chamaeleonidae
• East Usambara Mountains
• adult sex ratio
• radio-tracking
• generalized linear mixed models
• Trioceros deremensis
• pet trade
• Biology
• Life Sciences

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/390

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1389